Sensors for pressure, load, temperature, acceleration andmany other physical quantities often take the form of aWheatstone bridge. These sensors can be extremely linearand stable over time and temperature. However, mostthings in nature are only linear if you don’t bend them toomuch. In the case of a load cell, Hooke’s law states that thestrain in a material is proportional to the applied stress—as long as the stress is nowhere near the material’s yieldpoint (the “point of no return” where the material ispermanently deformed).
上傳時間： 2013-11-13
上傳用戶：墻角有棵樹
OPTOELECTRONICS CIRCUIT COLLECTION AVALANCHE PHOTODIODE BIAS SUPPLY 1Provides an output voltage of 0V to +80V for reverse biasingan avalanche photodiode to control its gain. This circuit canalso be reconfigured to supply a 0V to –80V output.LINEAR TEC DRIVER–1This is a bridge-tied load (BTL) linear amplifier for drivinga thermoelectric cooler (TEC). It operates on a single +5Vsupply and can drive ±2A into a common TEC.LINEAR TEC DRIVER–2This is very similar to DRIVER–1 but its power output stagewas modified to operate from a single +3.3V supply in orderto increase its efficiency. Driving this amplifier from astandard +2.5V referenced signal causes the output transistorsto have unequal power dissipation.LINEAR TEC DRIVER–3This BTL TEC driver power output stage achieves very highefficiency by swinging very close to its supply rails, ±2.5V.This driver can also drive ±2A into a common TEC. Operationis shown with the power output stage operating on±1.5V supplies. Under these conditions, this linear amplifiercan achieve very high efficiency. Application ReportThe following collection of analog circuits may be useful in electro-optics applications such as optical networkingsystems. This page summarizes their salient characteristics.
上傳時間： 2013-10-27
上傳用戶：落花無痕
模塊電源的電氣性能是通過一系列測試來呈現的，下列為一般的功能性測試項目，詳細說明如下： 電源調整率(Line Regulation) 負載調整率(load Regulation) 綜合調整率(Conmine Regulation) 輸出漣波及雜訊(Ripple & Noise) 輸入功率及效率(Input Power, Efficiency) 動態負載或暫態負載(Dynamic or Transient Response) 起動(Set-Up)及保持(Hold-Up)時間 常規功能(Functions)測試 1. 電源調整率 電源調整率的定義為電源供應器于輸入電壓變化時提供其穩定輸出電壓的能力。測試步驟如下：于待測電源供應器以正常輸入電壓及負載狀況下熱機穩定后，分別于低輸入電壓(Min)，正常輸入電壓(Normal)，及高輸入電壓(Max)下測量并記錄其輸出電壓值。 電源調整率通常以一正常之固定負載(Nominal load)下，由輸入電壓變化所造成其輸出電壓偏差率(deviation)的百分比，如下列公式所示： [Vo(max)-Vo(min)] / Vo(normal) 2. 負載調整率 負載調整率的定義為開關電源于輸出負載電流變化時，提供其穩定輸出電壓的能力。測試步驟如下：于待測電源供應器以正常輸入電壓及負載狀況下熱機穩定后，測量正常負載下之輸出電壓值，再分別于輕載(Min)、重載(Max)負載下，測量并記錄其輸出電壓值(分別為Vo(max)與Vo(min))，負載調整率通常以正常之固定輸入電壓下，由負載電流變化所造成其輸出電壓偏差率的百分比，如下列公式所示： [Vo(max)-Vo(min)] / Vo(normal) 3. 綜合調整率 綜合調整率的定義為電源供應器于輸入電壓與輸出負載電流變化時，提供其穩定輸出電壓的能力。這是電源調整率與負載調整率的綜合，此項測試系為上述電源調整率與負載調整率的綜合，可提供對電源供應器于改變輸入電壓與負載狀況下更正確的性能驗證。 綜合調整率用下列方式表示：于輸入電壓與輸出負載電流變化下，其輸出電壓之偏差量須于規定之上下限電壓范圍內(即輸出電壓之上下限絕對值以內)或某一百分比界限內。 4. 輸出雜訊 輸出雜訊(PARD)系指于輸入電壓與輸出負載電流均不變的情況下，其平均直流輸出電壓上的周期性與隨機性偏差量的電壓值。輸出雜訊是表示在經過穩壓及濾波后的直流輸出電壓上所有不需要的交流和噪聲部份(包含低頻之50/60Hz電源倍頻信號、高于20 KHz之高頻切換信號及其諧波，再與其它之隨機性信號所組成))，通常以mVp-p峰對峰值電壓為單位來表示。 一般的開關電源的規格均以輸出直流輸出電壓的1%以內為輸出雜訊之規格，其頻寬為20Hz到20MHz。電源實際工作時最惡劣的狀況(如輸出負載電流最大、輸入電源電壓最低等)，若電源供應器在惡劣環境狀況下，其輸出直流電壓加上雜訊后之輸出瞬時電壓，仍能夠維持穩定的輸出電壓不超過輸出高低電壓界限情形，否則將可能會導致電源電壓超過或低于邏輯電路(如TTL電路)之承受電源電壓而誤動作，進一步造成死機現象。 同時測量電路必須有良好的隔離處理及阻抗匹配，為避免導線上產生不必要的干擾、振鈴和駐波，一般都采用雙同軸電纜并以50Ω于其端點上，并使用差動式量測方法(可避免地回路之雜訊電流)，來獲得正確的測量結果。 5. 輸入功率與效率 電源供應器的輸入功率之定義為以下之公式： True Power = Pav(watt) = Vrms x Arms x Power Factor 即為對一周期內其輸入電壓與電流乘積之積分值，需注意的是Watt≠VrmsArms而是Watt=VrmsArmsxP.F.，其中P.F.為功率因素(Power Factor)，通常無功率因素校正電路電源供應器的功率因素在0.6～0.7左右，其功率因素為1～0之間。 電源供應器的效率之定義為為輸出直流功率之總和與輸入功率之比值。效率提供對電源供應器正確工作的驗證，若效率超過規定范圍，即表示設計或零件材料上有問題，效率太低時會導致散熱增加而影響其使用壽命。 6. 動態負載或暫態負載 一個定電壓輸出的電源，于設計中具備反饋控制回路，能夠將其輸出電壓連續不斷地維持穩定的輸出電壓。由于實際上反饋控制回路有一定的頻寬，因此限制了電源供應器對負載電流變化時的反應。若控制回路輸入與輸出之相移于增益(Unity Gain)為1時，超過180度，則電源供應器之輸出便會呈現不穩定、失控或振蕩之現象。實際上，電源供應器工作時的負載電流也是動態變化的，而不是始終維持不變(例如硬盤、軟驅、CPU或RAM動作等)，因此動態負載測試對電源供應器而言是極為重要的。可編程序電子負載可用來模擬電源供應器實際工作時最惡劣的負載情況，如負載電流迅速上升、下降之斜率、周期等，若電源供應器在惡劣負載狀況下，仍能夠維持穩定的輸出電壓不產生過高激(Overshoot)或過低(Undershoot)情形，否則會導致電源之輸出電壓超過負載組件(如TTL電路其輸出瞬時電壓應介于4.75V至5.25V之間，才不致引起TTL邏輯電路之誤動作)之承受電源電壓而誤動作，進一步造成死機現象。 7. 啟動時間與保持時間 啟動時間為電源供應器從輸入接上電源起到其輸出電壓上升到穩壓范圍內為止的時間，以一輸出為5V的電源供應器為例，啟動時間為從電源開機起到輸出電壓達到4.75V為止的時間。 保持時間為電源供應器從輸入切斷電源起到其輸出電壓下降到穩壓范圍外為止的時間，以一輸出為5V的電源供應器為例，保持時間為從關機起到輸出電壓低于4.75V為止的時間，一般值為17ms或20ms以上，以避免電力公司供電中于少了半周或一周之狀況下而受影響。 8. 其它 在電源具備一些特定保護功能的前提下，還需要進行保護功能測試，如過電壓保護(OVP)測試、短路保護測試、過功保護等
上傳時間： 2013-10-22
上傳用戶：zouxinwang
Abstract: This application note illustrates an intermediate 8V switching power supply for an automotive radio and infotainment system.The design withstands the complete automotive input voltage range (including cold crank and load dump conditions), assuring a stable8V supply for common subsystems such as a CD driver, LCDs, and a radio module in modern infotainment systems. To avoiddisturbance in the AM and FM bands, the switching power supply runs at a fixed frequency of 2MHz, enabling an ideal solution forradio systems.
上傳時間： 2013-11-20
上傳用戶：feitian920
精確度0.05%滿刻度±1位數（Accuracy 0.05%F.S.±1digit） 可測量交直流電流/交直流電壓/電位計/傳送器/Pt-100/荷重元/電阻等信號（Measuring DCA/DCV/ACA/ACV/Potentiometer/Transmitter/Pt-100/load Cell/Resistor/etc……） 顯示范圍0-19999可任意規劃（Programmable rate 0 to 1999 digit） 小數點可任意規劃（Decimal point can be modified） 尺寸小，穩定性高（Dimension small & High stability）
上傳時間： 2014-01-25
上傳用戶：RQB123
輸入電壓 5V/9V/12V/15V/24V DC 輸出電壓 3.3V/5V/9V/12V/15V/24V DC 如需其它規格,請咨詢順源科技公司 電氣特性 以下數據除特殊說明外,均是在TA=25° C, 標稱輸入電壓, 額定輸出電流時測得. 輸入特性 電壓范圍 +/- 10 % 濾波 陶瓷電容 隔離特性 額定電壓 1000 VDC 泄漏電流 1 m A 電阻 109 Ohm 電容 60 p TYP. 輸出特性 電壓精度 +/- 5 %, max. ( 20 MHz BW) 紋波及噪音 150mV p-p, max. 可持續短路時間 即時(
標簽： BxxxxLS-xW
上傳時間： 2014-09-09
上傳用戶：拔絲土豆
Abstract: With its small size and large load (10W) capability, the MAX13256 H-bridge transformer driver is an attractive solution forcharging supercapacitors (supercaps). However, a large capacitance on the output of the circuit can force the driver into fault modeat startup, due to the high initial charge current. This application note presents a solution that allows users to charge a largecapacitance without going into fault.
上傳時間： 2013-10-20
上傳用戶：2728460838
The LTC®3414 offers a compact and efficient voltage regulatorsolution for point of load conversion in electronicsystems that require low output voltages (down to 0.8V)from a 2.5V to 5V power bus. Internal power MOSFETswitches, with only 67mW on-resistance, allow theLTC3414 to deliver up to 4A of output current with efficiencyas high as 94%. The LTC3414 saves space by operatingwith switching frequencies as high as 4MHz, enabling theuse of tiny inductors and capacitors.
上傳時間： 2014-01-03
上傳用戶：dongbaobao
高的工作電壓高達100V N雙N溝道MOSFET同步驅動 The D810DCDC is a synchronous step-down switching regulator controller that can directly step-down voltages from up to 100V, making it ideal for telecom and automotive applications. The D810DCDC uses a constant on-time valley current control architecture to deliver very low duty cycles with accurate cycle-by-cycle current limit, without requiring a sense resistor. A precise internal reference provides 0.5% DC accuracy. A high bandwidth (25MHz) error amplifi er provides very fast line and load transient response. Large 1Ω gate drivers allow the D810DCDC to drive multiple MOSFETs for higher current applications. The operating frequency is selected by an external resistor and is compensated for variations in VIN and can also be synchronized to an external clock for switching-noise sensitive applications. Integrated bias control generates gate drive power from the input supply during start-up and when an output shortcircuit occurs, with the addition of a small external SOT23 MOSFET. When in regulation, power is derived from the output for higher effi ciency.
上傳時間： 2013-10-24
上傳用戶：wd450412225
Multiple-voltage electronics systems often requirecomplex supply voltage tracking or sequencing, whichif not met, can result in system faults or even permanentfailures in the fi eld. The design diffi culties in meetingthese requirements are often compounded in distributedpowerarchitectures where point-of-load (POL) DC/DCconverters or linear regulators are scattered across PCboard space, sometimes on different board planes. Theproblem is that power supply circuitry is often the lastcircuitry to be designed into the board, and it must beshoehorned into whatever little board real estate is left.Often, a simple, drop-in, fl exible solution is needed tomeet these requirements.
上傳時間： 2013-10-08
上傳用戶：15071087253
